Fucoidan as a marine anticancer agent in preclinical development

Fucoidan from seaweed Fucus vesiculosus inhibits 2,4-dinitrochlorobenzene-induced atopic dermatitis

Fucoidan, one activator of scavenger receptor class A (SR-A), plays important roles in a variety of biological activities, including anti-inflammatory, antioxidant, and antitumor actions. However, the effects of fucoidan on atopic dermatitis (AD) have not been elucidated. To assess this, 2,4-dinitrofluorobenzene (DNFB)-treated BALB/c mice were painted with fucoidan. Results showed that fucoidan significantly ameliorated ear swelling, improved abdomen skin lesions, and decreased inflammatory cell infiltration. In addition, fucoidan significantly suppressed the serum levels of IgE and IL-4 in DNFB-induced AD mice. The infiltration of CD4+ T cells in skin lesions and spleen was also reduced in fucoidan-treated AD mice. Furthermore, treatment with fucoidan promoted Treg cells but attenuated Th1/17 response in the spleens from DNFB-induced AD mice. Together, these results suggest that fucoidan, a natural seaweed-rich polysaccharide, has a potential therapeutic efficacy in the treatment of AD, correlates with the induction of higher anti-inflammatory response through inducing Treg cells.

Effects of Sulfated Fucans from Laminaria hyperborea Regarding VEGF Secretion, Cell Viability, and Oxidative Stress and Correlation with Molecular Weight

BACKGROUND

Sulfated fucans show interesting effects in the treatment of ocular diseases (e.g., age-related macular degeneration), depending on their chemical structure. Here, we compared three purified sulfated fucans from Laminaria hyperborea (LH) regarding cell viability, oxidative stress protection, and vascular endothelial growth factor (VEGF) secretion in ocular cells.

METHODS

High-molecular-weight sulfated fucan (Mw = 1548.6 kDa, Fuc1) was extracted with warm water and purified through ultrafiltration. Lower-molecular-weight samples (Mw = 499 kDa, Fuc2; 26.9 kDa, Fuc3) were obtained by mild acid hydrolysis of ultrapurified sulfated fucan and analyzed (SEC-MALS (Size-exclusion chromatography-Multi-Angle Light Scattering), ICP-MS, and GC). Concentrations between 1 and 100 µg/mL were tested. Cell viability was measured after 24 h (uveal melanoma cell line (OMM-1), retinal pigment epithelium (RPE) cell line ARPE-19, primary RPE cells) via MTT/MTS (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide/3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Oxidative stress protection was determined after 24 h (OMM-1, ARPE-19). VEGF secretion was analyzed via ELISA after three days (ARPE-19, RPE).

RESULTS

Fuc2 and Fuc3 were antiproliferative for OMM-1, but not for ARPE. Fuc1 protected OMM-1. VEGF secretion was lowered with all fucans except Fuc3 in ARPE-19 and RPE. The results suggest a correlation between molecular weight and biological activity, with efficiency increasing with size.

CONCLUSION

The LH sulfated fucan Fuc1 showed promising results regarding VEGF inhibition and protection, encouraging further medical research.

Fucoidan attenuates radioiodine-induced salivary gland dysfunction in mice

Background

Radioiodine (RI) treatments can destroy the cellular components of salivary glands (SG) and disrupt their function. This study investigated whether fucoidan could attenuate radioiodine-induced SG dysfunction in a mouse model.

Methods

Female C57BL/6 mice (n = 36) were classified into three groups; i) a normal (control) group, ii) an RI-treated group (0.2 mCi/20 g mouse, administered orally), and iii) a fucoidan and RI-treated group. Mice in each group were classified into three subgroups and sacrificed at 2, 4, and 12 weeks after RI treatment. The measurements of salivary flow rates and lag times and histomorphologic examinations were performed, and apoptotic assays were conducted. Changes in salivary ^99mTechnetium (Tc)-pertechnetate parameters using single-photon emission computed tomography were followed.

Results

Salivary flow rates and lag times in the fucoidan group were improved compared to the RI-treated group. Histologic examinations of SGs in the fucoidan group showed mucin-rich parenchymal areas and reduced periductal fibrosis as compared to the RI-treated group. Moreover, compared with the RI-treated group, fucoidan-treated groups showed evidence of cytoprotection, with a greater number of salivary epithelial cells and myoepithelial cells being observed. Fewer apoptotic cells were observed in the fucoidan group as compared to the RI group. The extent of ^99mTc pertechnetate excretion in the fucoidan group was similar to that of the control group.

Conclusion

Our results demonstrate that fucoidan administration before RI treatment could attenuate RI-induced SG damage and provides a possible candidate for preventing SG damage induced by RI.

In vitro anti-HIV-1 activity of the bioactive compound extracted and purified from two different marine macroalgae (seaweeds) (Dictyota bartayesiana J.V.Lamouroux and Turbinaria decurrens Bory)

Highly active antiretroviral therapy (HAART) is the only available remedial measure to treat HIV infected patients, as recognized by the WHO. However, it is associated with toxicity (nephrotoxicity), high cost and most preferably drug resistance in the first-line treatment. Wherefore, potential and novel natural source is the only option for the modern world to challenge this global issue. In recent years, sulfated polysaccharide from marine macroalgae shown to be biologically active as anti-inflammatory, anticoagulant, antitumor, immunomodulatory and antiviral agents. As a direct inhibitor of HIV including other retroviruses, it is considered as a "new generation antiretroviral drug". In our present study, Fucoidan, a sulfated polysaccharide has been extracted from two different macroalgae Dictyota bartayesiana (DD) and Turbinaria decurrens (TD) based on hot water extraction method and further confirmed by FT-IR and RP-HPLC methods. Both the crude and purified fucoidan samples were evaluated for anti-HIV activity after ion exchange chromatography purification. The maximum inhibitory activity of crude and purified fucoidan samples are 90.5% and 89% in the fucoidan extracts of DD. Whereas, it was 89.7% and 92% in the fucoidan extracts of TD. Simultaneously, the IC50 values were determined and recorded as 1.56 µg/ml and 57.6 ng/ml in both the crude and purified fucoidan extracts of DD respectively. Similarly, for TD, it was 3 µg/ml and 131.7 ng/ml in the fucoidan extracts of TD. Therefore, further extensive research work is the most needful to fill the gaps to develop this sulfated polysaccharide as a potential drug for the treatment of HIV patients.

Clinical applications of fucoidan in translational medicine for adjuvant cancer therapy

The chemical composition of fucoidan, a kind of sulfated polysaccharide mainly derived from brown seaweed, includes a substantial percentage of l-fucose. Fucoidan has various biological and pharmacological activities, such as anti-cancer/anti-tumor, anti-proliferation, anti-inflammatory and immune-modulatory functions, and fucoidan-related dietary supplements and nutraceuticals have recently drawn considerable attention. In this review, we aim to provide a current view of different aspects of fucoidan biological activity, with a focus on the anti-cancer regulatory effects of fucoidan on growth signaling mechanisms. First, we discuss historical aspects of fucoidan and fucoidan products, as well as the anti-cancer effects of fucoidan on various cancer cells. Second, we discuss fucoidan’s biological activities and induction of cell death in cancer cells, including multiple mechanisms and signal transduction pathways related to its anti-cancer effects. Next, we focus on fucoidan and fucoidan-derived products that have been marketed as dietary supplements or nutraceuticals for cancer, including anti-cancer effects of fucoidan when combined as an adjuvant with clinical drugs. Finally, case studies of fucoidan in complementary therapy and as an alternative medicine in animal and mouse models and human clinical trials to alleviate side effects of anti-cancer chemotherapy are discussed. Combining fucoidan with clinical therapeutic agents in the treatment of cancer patients, dissecting the related signal transduction pathways and investigating their dynamic interactions may reveal potential molecular targets in cancer prevention, therapies and key obstacles in the current development of anti-cancer strategies.

Ascophyllan Induces Activation of Natural Killer Cells in Mice In Vivo and In Vitro

Natural marine polysaccharides have demonstrated immune stimulatory effects in both mice and humans. Our previous study compared the ability of ascophyllan and fucoidan to activate human and mouse dendritic cells (DCs). In this study, we further examined the effect of ascophyllan on the activation of mouse natural killer (NK) cells in vivo and in vitro and compared it to that of fucoidan, a well-studied natural marine polysaccharide. Specifically, administration of ascophyllan to C57BL/6 mice increased the number of NK cells in the spleen when compared to the number in PBS-treated mice. Moreover, the number of IFN-γ-producing NK cells and expression of CD69 were markedly upregulated by ascophyllan treatment. Ascophyllan treatment also induced IFN-γ production and CD69 upregulation in isolated NK cells, but did not promote cell proliferation. Finally, ascophyllan treatment increased the cytotoxicity of NK cells against Yac-1 cells. The effects of ascophyllan on NK cell activation were considerably stronger than those of fucoidan. These data demonstrated that ascophyllan promotes NK cell activation both in mice and in vitro, and its stimulatory effect on NK cells is stronger than that of fucoidan.

Anaerobic Degradation of Sulfated Polysaccharides by Two Novel Kiritimatiellales Strains Isolated From Black Sea Sediment

The marine environment contains a large diversity of sulfated polysaccharides and other glycopolymers. Saccharolytic microorganisms degrade these compounds through hydrolysis, which includes the hydrolysis of sulfate groups from sugars by sulfatases. Various marine bacteria of the Planctomycetes-Verrucomicrobia-Chlamydia (PVC) superphylum have exceptionally high numbers of sulfatase genes associated with the degradation of sulfated polysaccharides. However, thus far no sulfatase-rich marine anaerobes are known. In this study, we aimed to isolate marine anaerobes using sulfated polysaccharides as substrate. Anoxic enrichment cultures were set up with a mineral brackish marine medium, inoculated with anoxic Black Sea sediment sampled at 2,100 m water depth water and incubated at 15°C (in situ T = 8°C) for several weeks. Community analysis by 16S rRNA gene amplicon sequencing revealed the enrichment of Kiritimatiellaeota clade R76-B128 bacteria in the enrichments with the sulfated polysaccharides fucoidan and iota-carrageenan as substrate. We isolated two strains, F1 and F21, which represent a novel family within the order of the Kiritimatiellales. They were capable of growth on various mono-, di-, and polysaccharides, including fucoidan. The desulfation of iota-carrageenan by strain F21 was confirmed quantitatively by an increase in free sulfate concentration. Strains F1 and F21 represent the first marine sulfatase-rich anaerobes, encoding more sulfatases (521 and 480, 8.0 and 8.4% of all coding sequences, respectively) than any other microorganism currently known. Specific encoded sulfatase subfamilies could be involved in desulfating fucoidan (S1_15, S1_17 and S1_25) and iota-carrageenan (S1_19). Strains F1 and F21 had a sulfatase gene classification profile more similar to aerobic than anaerobic sulfatase-rich PVC bacteria, including Kiritimatiella glycovorans, the only other cultured representative within the Kiritimatiellaeota. Both strains encoded a single anaerobic sulfatase-maturating enzyme which could be responsible for post-translational modification of formylglycine-dependent sulfatases. Strains F1 and F21 are potential anaerobic platforms for future studies on sulfatases and their maturation enzymes.

Activation of Human Dendritic Cells by Ascophyllan Purified from Ascophyllum nodosum

In our previous study, we showed that ascophyllan purified from Ascophyllum nodosum treatment promotes mouse dendritic cell (DC) activation in vivo, further induces an antigen-specific immune response and has anticancer effects in mice. However, the effect of ascophyllan has not been studied in human immune cells, specifically in terms of activation of human monocyte-derived DCs (MDDCs) and human peripheral blood DCs (PBDCs). We found that the treatment with ascophyllan induced morphological changes in MDDCs and upregulated co-stimulatory molecules and major histocompatibility complex class I (MHC I) and MHC II expression. In addition, pro-inflammatory cytokine levels in culture medium was also dramatically increased following ascophyllan treatment of MDDCs. Moreover, ascophyllan promoted phosphorylation of ERK, p38 and JNK signaling pathways, and inhibition of p38 almost completely suppressed the ascophyllan-induced activation of MDDCs. Finally, treatment with ascophyllan induced activation of BDCA1 and BDCA3 PBDCs. Thus, these data suggest that ascophyllan could be used as an immune stimulator in humans.

Pathway Analysis of Fucoidan Activity Using a Yeast Gene Deletion Library Screen

Fucoidan, the sulfated fucose-rich polysaccharide derived from brown macroalgae, was reported to display some anti-cancer effects in in vitro and in vivo models that included apoptosis and cell cycle arrest. The proposed mechanisms of action involve enhanced immune surveillance and direct pro-apoptotic effects via the activation of cell signaling pathways that remain largely uncharacterized. This study aimed to identify cellular pathways influenced by fucoidan using an unbiased genetic approach to generate additional insights into the anti-cancer effects of fucoidan. Drug⁻gene interactions of Undaria pinnatifida fucoidan were assessed by a systematic screen of the entire set of 4,733 halpoid Saccharomyces cerevsiae gene deletion strains. Some of the findings were confirmed using cell cycle analysis and DNA damage detection in non-immortalized human dermal fibroblasts and colon cancer cells. The yeast deletion library screen and subsequent pathway and interactome analysis identified global effects of fucoidan on a wide range of eukaryotic cellular processes, including RNA metabolism, protein synthesis, sorting, targeting and transport, carbohydrate metabolism, mitochondrial maintenance, cell cycle regulation, and DNA damage repair-related pathways. Fucoidan also reduced clonogenic survival, induced DNA damage and G1-arrest in colon cancer cells, while these effects were not observed in non-immortalized human fibroblasts. Our results demonstrate global effects of fucoidan in diverse cellular processes in eukaryotic cells and further our understanding about the inhibitory effect of Undaria pinnatifida fucoidan on the growth of human cancer cells.

Applications of Algal Polysaccharides and Derivatives in Therapeutic and Agricultural Fields

BACKGROUND

Recently, researchers have given more and more consideration to natural polysaccharides thanks to their huge properties such as stability, biodegradability and biocompatibility for food and therapeutics applications.

METHODS

a number of enzymatic and chemical processes were performed to generate bioactive molecules, such as low molecular weight fractions and oligosaccharides derivatives from algal polysaccharides.

RESULTS

These considerable characteristics allow algal polysaccharides and their derivatives such as low molecular weight polymers and oligosaccharides structures to have great potential to be used in lots of domains, such as pharmaceutics and agriculture etc. Conclusion: The present review describes the mains polysaccharides structures from Algae and focuses on the currents agricultural (fertilizer, bio-elicitor, stimulators, signaling molecules and activators) and pharmaceutical (wound dressing, tissues engineering and drugs delivery) applications by using polysaccharides and/or their oligosaccharides derivatives obtained by chemical, physical and enzymatic processes.

Fucoidan Exerts Anticancer Effects Against Head and Neck Squamous Cell Carcinoma In Vitro

Fucoidans have been reported to exert anticancer effects with simultaneous low toxicity against healthy tissue. That correlation was observed in several cancer models, however, it has never been investigated in head and neck cancer before. To magnify the efficacy of conventional therapy, the administration of agents like fucoidan could be beneficial. The aim of this study was to evaluate the anticancer effect of Fucus vesiculosus (FV) extract alone and with co-administration of cisplatin in head and neck squamous cell carcinoma (HNSCC) in vitro. MTT assay results revealed an FV-induced inhibition of proliferation in all tested cell lines (H103, FaDu, KB). Flow cytometric cell cycle analysis showed an FV-induced, dose-dependent arrest in either S/G2 phase (H103, FaDu) or G1 arrest (KB). Furthermore, a dose-dependent gain in apoptotic fraction was observed. Western blot analysis confirmed the induction of apoptosis. A significant dose-dependent increase in reactive oxygen species (ROS) production was revealed in the H103 cell line, while FaDu cells remained unresponsive. On the contrary, an HPV-positive cell line, KB, demonstrated a dose-dependent decrease in ROS synthesis. Moreover, fucoidan enhanced the response to cisplatin (synergistic effect) in all cell lines with the HPV-positive one (KB) being the most sensitive. These results have been confirmed by flow-cytometric apoptosis analysis. In conclusion, we confirmed that fucoidan exhibits anticancer properties against HNSCC, which are manifested by the induction of apoptosis, regulation of ROS production, cell cycle arrest, and inhibition of proliferation.

Low Molecular Weight Mannogalactofucans Derived from Undaria pinnatifida Induce Apoptotic Death of Human Prostate Cancer Cells In Vitro and In Vivo

Low molecular weight mannogalactofucans (LMMGFs) prepared by enzymatic degradation of high molecular weight Undaria galactofucan (MF) were evaluated for their anti-cancer effects against human prostate cancer. Correlation NMR and linkage analyses confirmed that LMMGFs consist mainly of α-fucose and β-galactose units: α-fucose units are 1,3-linked; β-galactose units are terminal, 1,3- and/or 1,6-linked; both sugars are partially sulphated, fucose at positions O-2 and/or O-4 and galactose at O-3. Mannose residue, as a minor sugar, presents as the 1,4-linked terminal units. LMMGFs more significantly induced cell cycle arrest at the G0/G1 phase and cell death via suppression of the Akt/GSK-3β/β-catenin pathway than MF in human PC-3 prostate cancer cells. LMMGFs upregulated mRNA expression of death receptor-5 (DR-5), the ratio of Bax to Bcl-2, the cleavage of caspases and PARP, the depolarisation of mitochondrial membrane potential, and ROS generation. LMMGFs (200-400 mg/kg) effectively reduced both tumour volume and size in a xenografted mouse model. These results demonstrated that LMMGFs attenuate the growth of human prostate cancer cells both in vitro and in vivo, suggesting that LMMGFs can be used as a potent functional ingredient in health-beneficial foods or as a therapeutic agent to prevent or treat androgen-independent human prostate cancer. Graphical Abstract.

Spray-dried fucoidan microparticles for pulmonary delivery of antitubercular drugs

Pulmonary tuberculosis accounts for 80% of cases and the delivery of antitubercular drugs into the lungs allows targeting the infected organ and, possibly, reducing systemic drug toxicity. This work aimed at using fucoidan as matrix of inhalable microparticles that associate two first-line antitubercular drugs, for an application in pulmonary tuberculosis therapy. Fucoidan is composed of fucose and sulphated sugar residues, moieties described as being recognised by surface receptors of alveolar macrophages, which host mycobacteria. Inhalable fucoidan microparticles loaded with antitubercular drugs were successfully produced with high association efficiencies of either isoniazid (95%) or rifabutin (81%). The microparticles evidenced no cytotoxicity on lung epithelial cells (A549). However, rifabutin-loaded microparticles showed a certain degree of toxicity on macrophage-like cells (THP-1) at the highest tested concentration (1 mg/mL). Furthermore, microparticles showed favourable aerodynamic properties for deep lung delivery (MMAD 2.0-3.8 µm) and, thus, show potential for an application as inhalable tuberculosis therapy.

Fucoidan Extracted from the New Zealand Undaria pinnatifida-Physicochemical Comparison against Five Other Fucoidans: Unique Low Molecular Weight Fraction Bioactivity in Breast Cancer Cell Lines

Fucoidan, the complex fucose-containing sulphated polysaccharide varies considerably in structure, composition, and bioactivity, depending on the source, species, seasonality, and extraction method. In this study, we examined five fucoidans extracted from the same seaweed species Undaria pinnatifida but from different geological locations, and compared them to the laboratory-grade fucoidan from Sigma (S). The five products differed in molecular composition. The amount of over 2 kDa low molecular weight fraction (LMWF) of the New Zealand crude fucoidan (S1) was larger than that of S, and this fraction was unique, compared to the other four fucoidans. The difference of molecular compositions between S and S1 explained our previous observation that S1 exhibited different anticancer profile in some cancer cell lines, compared with S. Since we observed this unique LMWF, we compared the cytotoxic effects of a LMWF and a high molecular weight fucoidan (HMWF) in two breast cancer cell lines-MCF-7 and MDA-MB-231. Results indicated that the molecular weight is a critical factor in determining the anti-cancer potential of fucoidan, from the New Zealand U. pinnatifida, as the LMWF exhibited a dose-dependent inhibition on the proliferation of breast cancer cells, significantly better than the HMWF, in both cell lines. A time-dependent inhibition was only observed in the MCF-7. Induction of caspase-dependent apoptosis was observed in the MDA-MB-231 cells, through the intrinsic apoptosis pathway alone, or with the extrinsic pathway. LMWF stimulated a dose-dependent NOS activation in the MDA-MB-231 cells. In conclusion, the fucoidan extracted from the New Zealand U. pinnatifida contains a unique LMWF, which could effectively inhibit the growth of breast cancer cell lines. Therefore, the LMWF from New Zealand U. pinnatifida could be used as a supplement cancer treatment.

State-of-the-Art Extraction Methodologies for Bioactive Compounds from Algal Biome to Meet Bio-Economy Challenges and Opportunities

Over the years, significant research efforts have been made to extract bioactive compounds by applying different methodologies for various applications. For instance, the use of bioactive compounds in several commercial sectors such as biomedical, pharmaceutical, cosmeceutical, nutraceutical and chemical industries, has promoted the need of the most suitable and standardized methods to extract these bioactive constituents in a sophisticated and cost-effective manner. In practice, several conventional extraction methods have numerous limitations, e.g., lower efficacy, high energy cost, low yield, etc., thus urges for new state-of-the-art extraction methodologies. Thus, the optimization along with the integration of efficient pretreatment strategies followed by traditional extraction and purification processes, have been the primary goal of current research and development studies. Among different sources, algal biome has been found as a promising and feasible source to extract a broader spectrum of bioactive compounds with point-of-care application potentialities. As evident from the literature, algal bio-products includes biofuels, lipids, polyunsaturated fatty acids, pigments, enzymes, polysaccharides, and proteins. The recovery of products from algal biomass is a matter of constant development and progress. This review covers recent advancements in the extraction methodologies such as enzyme-assisted extraction (EAE), supercritical-fluid extraction (SFE), microwave-assisted extraction (MAE) and pressurized-liquid extraction (PLF) along with their working mechanism for extracting bioactive compounds from algal-based sources to meet bio-economy challenges and opportunities. A particular focus has been given to design characteristics, performance evaluation, and point-of-care applications of different bioactive compounds of microalgae. The previous and recent studies on the anticancer, antibacterial, and antiviral potentialities of algal-based bioactive compounds have also been discussed with particular reference to the mechanism underlying the effects of these active constituents with the related pathways. Towards the end, the information is also given on the possible research gaps, future perspectives and concluding remarks.

Fucoidan Inhibits Radiation-Induced Pneumonitis and Lung Fibrosis by Reducing Inflammatory Cytokine Expression in Lung Tissues

Purpose: Radiotherapy is a crucial treatment approach for many types of cancer. Radiation pneumonitis (RP) is one of the major complications in chest irradiation. Fucoidan is a sulfated polysaccharide found mainly in various species of brown seaweed. Recent studies have demonstrated the anti-inflammatory effects of fucoidan. However, no study has reported a well-established prophylactic agent for RP. Therefore, we investigated the effects of fucoidan on RP and radiotherapy (RT)-induced lung fibrosis. Materials and Methods: We compared RP and RT-induced fibrosis in lung tissue specimens obtained from irradiated (10 Gy/shot) C57BL/6 mice with or without fucoidan administration (200 mg/kg/day, oral gavage for 14 days). The expression patterns of cytokines in the pleural fluid were determined using a cytokine array and confirmed through enzyme immunoassays. Results: Fucoidan administration attenuated RP and RT-induced fibrosis in lung tissues. Decreased neutrophil and macrophage accumulation was observed in irradiated lung tissues, and radiation-induced lung fibrosis, as demonstrated by Masson trichrome staining, was attenuated. We investigated the expression patterns of inflammatory cytokines in the irradiated lung pleural fluid through the protein array; results revealed that fucoidan administration changed the expression patterns of inflammatory cytokines in irradiated lung tissues. Furthermore, the expression levels of TIMP-1, CXCL1, MCP-1, MIP-2, and interleukin-1Ra were substantially enhanced in the pleural fluid, but fucoidan administration significantly reduced their expression. Conclusions: Fucoidan changes the expression patterns of inflammatory cytokines, which may consequently attenuate RP and RT-induced lung fibrosis.

Evaluation Fucoidan Extracts From Undaria pinnatifida and Fucus vesiculosus in Combination With Anticancer Drugs in Human Cancer Orthotopic Mouse Models

OBJECTIVE

To determine the activity of fucoidan from Undaria pinnatifida (UPF) and Fucus vesiculosus (FVF) when given in combination of chemotherapy drugs using selected human breast or ovarian cancer orthotopic mouse models.

METHODS

Mice were inoculated with 1 × 106 cells of TOV-112d, MCF-7, or ZR-75 subcutaneously or SKOV3-GFP-Luc intraperitoneally on day 0. MCF-7 and ZR-75 mice were administered with estradiol valerate 2 mg/kg in 0.2 mL castor oil subcutaneously two days prior to cell inoculation. Mice were randomized to one of six arms (N = 10/arm) paclitaxel, UPF/paclitaxel, FVF/paclitaxel, tamoxifen, UPF/tamoxifen, or FVF/tamoxifen. Tumors were measured three times per week for 28 days.

RESULTS

Improved activity was observed with UPF or FVF in combination with tamoxifen in both the MCF-7 and ZR-75D breast cancer mouse models. Decreased activity of paclitaxel was observed when given in combination with UPF or FVF in both breast cancer mouse models. The combination of FVF/tamoxifen in the TOV-112d ovarian cancer mouse model had improved activity but no there was difference observed with the UPF/tamoxifen in either ovarian cancer mouse model. No difference was observed with combination of UPF or FVF with paclitaxel in human ovarian cancer SKOV3 or TOV-112d orthotopic mouse models.

CONCLUSION

This study did confirm that UPF/FVF in combination with tamoxifen did not decrease tamoxifen activity in both breast and ovarian cancer, with some potential to improve activity compared to tamoxifen alone in breast cancers. Previous in vitro studies had suggested UPF and FVF had overall synergistic activity with paclitaxel; however, in the current in vivo human cancer mouse model studies there was no change in paclitaxel activity when given in combination with UPF or FVF in either of the two human ovarian cancer models. Furthermore, this study demonstrated that UPF or FVF given in combination with paclitaxel had a potential antagonistic effect in breast cancer models. Additional studies are warranted to delineate mechanisms contributing to variation in the in vivo activity when given in combination with paclitaxel. As a first step, a clinical pharmacokinetic study evaluating impact of FVF/UPF given in combination with chemotherapy in patients with solid tumors is underway.

From Marine Origin to Therapeutics: The Antitumor Potential of Marine Algae-Derived Compounds

Marine environment has demonstrated to be an interesting source of compounds with uncommon and unique chemical features on which the molecular modeling and chemical synthesis of new drugs can be based with greater efficacy and specificity for the therapeutics. Cancer is a growing public health threat, and despite the advances in biomedical research and technology, there is an urgent need for the development of new anticancer drugs. In this field, it is estimated that more than 60% of commercially available anticancer drugs are natural biomimetic inspired. Among the marine organisms, algae have revealed to be one of the major sources of new compounds of marine origin, including those exhibiting antitumor and cytotoxic potential. These compounds demonstrated ability to mediate specific inhibitory activities on a number of key cellular processes, including apoptosis pathways, angiogenesis, migration and invasion, in both in vitro and in vivo models, revealing their potential to be used as anticancer drugs. This review will focus on the bioactive molecules from algae with antitumor potential, from their origin to their potential uses, with special emphasis to the alga Sphaerococcus coronopifolius as a producer of cytotoxic compounds.

Combination of fucoidan-based magnetic nanoparticles and immunomodulators enhances tumour-localized immunotherapy

Checkpoint immunotherapy that inhibits tumour immune evasion has demonstrated significant clinical success. However, the therapeutic response is limited to certain patient populations, and immunotoxicity as well as autoimmunity have compromised the therapeutic benefits. Here, we report on an inherently therapeutic fucoidan-dextran-based magnetic nanomedicine (IO@FuDex³) conjugated with a checkpoint inhibitor (anti-PD-L1) and T-cell activators (anti-CD3 and anti-CD28). IO@FuDex³ can repair the immunosuppressive tumour microenvironment by reinvigorating tumour-infiltrating lymphocytes, while targeting the nanomedicine via magnetic navigation to the tumour to minimize off-target effects. Treatment that combines IO@FuDex³ and magnetic navigation reduces the occurrence of adverse events and extends the median survival from 32 to 63 days with less than 1 per cent dose compared with soluble anti-PD-L1. Thus, we demonstrate the potential of integrating anti-PD-L1 and T-cell activators as a form of inherently therapeutic nanomedicine to augment the therapeutic index of combination checkpoint immunotherapy.

Phycochemical Constituents and Biological Activities of Fucus spp

Seaweeds are known to be a good supply of key nutrients including carbohydrates, protein, minerals, polyunsaturated lipids, as well as several other health-promoting compounds capable of acting on a wide spectrum of disorders and/or diseases. While these marine macroalgae are deeply rooted in the East Asian culture and dietary habits, their major application in Western countries has been in the phycocolloid industry. This scenario has however been gradually changing, since seaweed consumption is becoming more common worldwide. Among the numerous edible seaweeds, members of the genus Fucus have a high nutritional value and are considered good sources of dietary fibers and minerals, especially iodine. Additionally, their wealth of bioactive compounds such as fucoidan, phlorotannins, fucoxanthin and others make them strong candidates for multiple therapeutic applications (e.g., antioxidant, anti-inflammatory, anti-tumor, anti-obesity, anti-coagulant, anti-diabetes and others). This review presents an overview of the nutritional and phytochemical composition of Fucus spp., and their claimed biological activities, as well as the beneficial effects associated to their consumption. Furthermore, the use of Fucus seaweeds and/or their components as functional ingredients for formulation of novel and enhanced foods is also discussed.

Proteomic analyses for profiling regulated proteins/enzymes by Fucus vesiculosus fucoidan in B16 melanoma cells: A combination of enzyme kinetics functional study

Fucoidans are complex sulfated polysaccharides that have a wide range of biological activities. Previously, we reported the various effects of Fucus vesiculosus fucoidan on tyrosinase and B16 melanoma cells. In this study, to identify fucoidan-targeted proteins in B16 melanoma cells, we performed a proteomics study and integrated enzyme kinetics. We detected 19 candidate proteins dysregulated by fucoidan treatment. Among the probed proteins, the enzyme kinetics of two candidate enzymes, namely lactate dehydrogenase (LDH) as an upregulated protein and superoxide dismutase (SOD) as a downregulated enzyme, were determined. The enzyme kinetics results showed that Fucus vesiculosus fucoidan significantly inhibited LDH catalytic function while it did not affect SOD activity even at a high dose, while only slightly decreased activity (up to 10%) at a low dose. Based on our previous and present observations, fucoidan could inhibit B16 melanoma cells growth via regulating proteins/enzymes expression levels such as LDH and SOD known as cell survival biomarkers. Interestingly, both expression level and enzyme catalytic activity of LDH were regulated by fucoidan, which could directly induce the apoptotic effect on B16 melanoma cells along with SOD downregulation. This study highlights how combining proteomics with enzyme kinetics can yield valuable insights into fucoidan targets.

Poly-L-ornithine/fucoidan-coated calcium carbonate microparticles by layer-by-layer self-assembly technique for cancer theranostics

Recently, the layer-by-layer (LbL) self-assembly technology has attracted the enormous interest of researchers in synthesizing various pharmaceutical dosage forms. Herewith, we designed a biocompatible drug delivery system containing the calcium carbonate microparticles (CaCO₃ MPs) that coated with the alternatively charged polyelectrolytes, i.e., poly-L-ornithine (PLO)/fucoidan by LbL self-assembly process (LbL MPs). Upon coating with the polyelectrolytes, the mean particle size of MPs obtained from SEM observations increased from 1.91 to 2.03 μm, and the surface of LbL MPs was smoothened compared to naked CaCO₃ MPs. In addition, the reversible zeta potential changes have confirmed the accomplishment of layer upon a layer assembly. To evaluate the efficiency of cancer therapeutics, we loaded doxorubicin (Dox) in the LbL MPs, which resulted in high (69.7%) drug encapsulation efficiency. The controlled release of Dox resulted in the significant antiproliferative efficiency in breast cancer cell line (MCF-7 cells), demonstrating the potential of applying this innovative drug delivery system in the biomedical field.

Purification, molecular properties, structural characterization, and immunomodulatory activities of water soluble polysaccharides from Sargassum angustifolium

Sulfated polysaccharides isolated from Sargassum angustifolium and purified to determine their structural characteristics and biological activities. Crude polysaccharides and fractions (F1 and F2) were chiefly composed of neutral sugars (49.4-68.5%) and sulfates (12.5-23.0%) along with small amounts of uronic acids (1.3-13.6%) and proteins (4.1-4.7%). Polysaccharides were mainly constructed of different levels of fucose (23.9-69.9%) and galactose (22.5-29.8%) sugars. Subfractions with molecular weights ranging from 157.2 to 790.8×103g/mol were identified for isolated polysaccharides. Polysaccharides induced RAW264.7 macrophage cells to release noticeable amounts of nitric oxide and cytokines including IL-1β, TNF-α, IL-6, IL-10 and IL-12 through NF-κB and MAPKs signaling pathways. Sulfate esters of fraction F2 were necessary to its bioactivity and they were located on carbons 2, 4 and 6 of the major sugars. Fraction F2 was formed of (1→4)- and (1→3)-linked fucose residues branched at C-2 and C-4 as well as (1→6)-linked galactose residues branched at C-3.

The Effect of Undaria pinnatifida Fucoidan on the Pharmacokinetics of Letrozole and Tamoxifen in Patients With Breast Cancer

BACKGROUND

Although the use of complementary and alternative medicines is widespread in cancer patients, clinical evidence of their benefits is sparse. Furthermore, while they are often assumed to be safe with regard to concurrent use of anticancer therapies, few studies have been carried out to investigate possible interactions. Fucoidans are a group of sulfated carbohydrates, derived from marine brown algae, which have long been used as dietary supplements due to their reported medicinal properties, including anticancer activity. The aim of this study was to investigate the effect of co-administration of fucoidan, derived from Undaria pinnatifida, on the pharmacokinetics of 2 commonly used hormonal therapies, letrozole and tamoxifen, in patients with breast cancer.

METHODS

This was an open label non-crossover study in patients with active malignancy taking letrozole or tamoxifen (n = 10 for each group). Patients took oral fucoidan, given in the form of Maritech extract, for a 3-week period (500 mg twice daily). Trough plasma concentrations of letrozole, tamoxifen, 4-hydroxytamoxifen, and endoxifen were measured using HPLC-CAD (high-performance liquid chromatography charged aerosol detector), at baseline and after concomitant administration with fucoidan.

RESULTS

No significant changes in steady-state plasma concentrations of letrozole, tamoxifen, or tamoxifen metabolites were detected after co-administration with fucoidan. In addition, no adverse effects of fucoidan were reported, and toxicity monitoring showed no significant differences in all parameters measured over the study period.

CONCLUSIONS

Administration of Undaria pinnatifida fucoidan had no significant effect on the steady-state trough concentrations of letrozole or tamoxifen and was well tolerated. These results suggest that fucoidan in the studied form and dosage could be taken concomitantly with letrozole and tamoxifen without the risk of clinically significant interactions.

Fucoidan Prolongs the Circulation Time of Dextran-Coated Iron Oxide Nanoparticles

The magnetic properties and safety of dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs) have facilitated their clinical use as MRI contrast agents and stimulated research on applications for SPIONs in particle imaging and magnetic hyperthermia. The wider clinical potential of SPIONs, however, has been limited by their rapid removal from circulation via the reticuloendothelial system (RES). We explored the possibility of extending SPION circulatory time using fucoidan, a seaweed-derived food supplement, to inhibit RES uptake. The effects of fucoidan on SPION biodistribution were evaluated using ferucarbotran, which in its pharmaceutical formulation (Resovist) targets the RES. Ferucarbotran was radiolabeled at the iron oxide core with technetium-99m (99mTc; t1/2 = 6 h) or zirconium-89 (89Zr; t1/2 = 3.3 days). Results obtained with 99mTc-ferucarbotran demonstrated that administration of fucoidan led to a 4-fold increase in the circulatory half-life (t1/2 slow) from 37.4 to 150 min (n = 4; P < 0.0001). To investigate whether a longer circulatory half-life could lead to concomitant increased tumor uptake, the effects of fucoidan were tested with 89Zr-ferucarbotran in mice bearing syngeneic subcutaneous (GL261) tumors. In this model, the longer circulatory half-life achieved with fucoidan was associated with a doubling in tumor SPION uptake (n = 5; P < 0.001). Fucoidan was also effective in significantly increasing the circulatory half-life of perimag-COOH, a commercially available SPION with a larger hydrodynamic size (130 nm) than ferucarbotran (65 nm). These findings indicate successful diversion of SPIONs away from the hepatic RES and show realistic potential for future clinical applications.

Fucoidan enhances the therapeutic potential of arsenic trioxide and all-trans retinoic acid in acute promyelocytic leukemia, in vitro and in vivo

The morbidity and mortality associated with current therapies for acute promyelocytic leukemia (APL) remain a significant clinical concern, despite improvements in patient survival. Consequently, the development of adjuvant therapies that increase efficacy while reducing morbidities is important. Reducing the concentration of the toxic drugs in adjuvant therapy has the potential to reduce unwanted side effects. Therefore, this study aimed to determine the synergistic effects of fucoidan, an anti-tumor agent, with current APL therapies.When the human APL cell line, NB4, was treated in vitro with fucoidan plus ATO and ATRA at therapeutic and sub-therapeutic doses, there was an increase in sub-G0/G1 cells, annexin V/PI-positive-apoptotic cells and DNA fragmentation. This reduction in proliferation and increase in apoptosis was accompanied by enhanced myeloid differentiation as indicated by an increased expression of CD11b. This was not observed with the AML cell line Kasumi-1, suggesting specificity for APL.In vivo treatment of APL-bearing mice with fucoidan+ATRA or fucoidan+ATO delayed tumor growth, induced differentiation and increased tumor volume doubling time. The differentiated APL cells derived from the excised tumor mass exhibited decreased CD44 expression in fucoidan+ATRA treated mice. This could translate to decreased cell migration in APL patients.Our findings provide evidence supporting the use of fucoidan as an adjuvant therapeutic agent in the treatment of APL.

Antiviral activity of a polysaccharide from Laminaria japonica against enterovirus 71

This in vitro study investigated the antiviral activity of an acidic polysaccharide from Laminaria japonica against enterovirus 71 (EV71) as well as its mechanism of action. The LJ04 polysaccharide was purified from Laminaria japonica by affinity chromatography. To investigate its antiviral activity, an MTT assay, q-PCR, immunofluorescent staining and western-blot analysis were performed. To define its mechanism of action, ELISA, q-PCR and flow cytometry were conducted. LJ04 had a low EC50, high CC50 and high SI. LJ04 inhibited not only JN200804, but also JN200803 in RD cells, and viral proliferation was strongly inhibited, whereas LJ04 suppressed viral-induced apoptosis as detected by flow cytometry. In conclusion, LJ04 was found to have robust antiviral activity by inhibiting apoptosis and inducing IFN-β expression. Our findings indicate that LJ04 is a good candidate for the treatment of EV71.

A review about brown algal cell walls and fucose-containing sulfated polysaccharides: Cell wall context, biomedical properties and key research challenges

Studies on brown algal cell walls have entered a new phase with the concomitant discovery of novel polysaccharides present in cell walls and the establishment of a comprehensive generic model for cell wall architecture. Brown algal cell walls are composites of structurally complex polysaccharides. In this review we discuss the most recent progress in the structural composition of brown algal cell walls, emphasizing the significance of extraction and screening techniques, and the biological activities of the corresponding polysaccharides, with a specific focus on the fucose-containing sulfated polysaccharides. They include valuable marine molecules that exert a broad range of pharmacological properties such as antioxidant and anti-inflammatory activities, functions in the regulation of immune responses and of haemostasis, anti-infectious and anticancer actions. We identify the key remaining challenges in this research field.

In vitro and in vivo anti-primary effusion lymphoma activities of fucoidan extracted from Cladosiphon okamuranus Tokida

Primary effusion lymphoma (PEL) caused by Kaposi's sarcoma-associated herpesvirus (KSHV) is characterized by lymphomatous effusion in body cavities and poor prognosis. There is still no effective treatment for PEL. Fucoidan, a major sulfated polysaccharide isolated from brown seaweeds, has an attractive array of bioactivities such as cancer inhibition. However, the effects of fucoidan on PEL cells remain unclear. We investigated the anti-PEL effects of fucoidan obtained from Cladosiphon okamuranus Tokida cultivated in Okinawa. Fucoidan dose-dependently inhibited the proliferation of KSHV-infected PEL cell lines, and provoked G1 cell cycle arrest, which was accompanied by CDK4 and CDK6 downregulation. Fucoidan also induced apoptosis of PEL cells through caspase-3, -8 and -9 activation; this occurred partly through the downregulation of anti-apoptotic Bcl-xL, Mcl-1 and XIAP proteins. Fucoidan also suppressed nuclear factor-κB, activator protein-1 (AP-1), and T-lymphokine-activated killer cell-originated protein kinase (TOPK) signaling pathways through inhibition of phosphorylation of IκBα and TOPK, and the expression of AP-1 family proteins, JunB and JunD. Oral administration of fucoidan effectively inhibited the development of PEL cells and ascites in a xenograft SCID mouse model, with minimal serious adverse effects. Notably, native fucoidan exhibited a more efficient anti-PEL effect than nanoparticle fucoidan. These preclinical findings highlight the anti-PEL actions of fucoidan, suggesting it could be potentially useful for the prevention and treatment of PEL.

Potential biomedical applications of marine algae

Functional components extracted from algal biomass are widely used as dietary and health supplements with a variety of applications in food science and technology. In contrast, the applications of algae in dermal-related products have received much less attention, despite that algae also possess high potential for the uses in anti-infection, anti-aging, skin-whitening, and skin tumor treatments. This review, therefore, focuses on integrating studies on algae pertinent to human skin care, health and therapy. The active compounds in algae related to human skin treatments are mentioned and the possible mechanisms involved are described. The main purpose of this review is to identify serviceable algae functions in skin treatments to facilitate practical applications in this high-potential area.

Sulfated polysaccharides of the Vietnamese brown alga Sargassum aquifolium (Fucales, Sargassaceae)

A fucoidan preparation named FSA was isolated from the brown alga Sargassum aquifolium collected from the coastal waters of Vietnam. l-Fucose, d-galactose, d-mannose, d-glucuronic acid, d-xylose, and sulfate were found to be the main constituents of FSA. The preparation was fractionated by anion-exchange chromatography on DEAE-Sephacel eluted stepwise with 0.5, 1.0, 1.5, and 2.0 M NaCl to give four fractions differing in monosaccharide composition and degree of sulfation. Their NMR spectra were too complex to be completely interpreted. Fractions 1.0 M and 1.5 M were analyzed by methylation before and after desulfation. In addition, desulfated 1.0 M was fractionated by anion-exchange chromatography into six fractions according to the uronic acid content. They were characterized by methylation and NMR spectral data, and three structurally different polysaccharides were identified. One of them has a core of alternating 2-linked α-d-Manp and 4-linked β-d-GlcpA residues, about a half of the former bearing single α-l-Fucp or β-d-Xylp at position 3. The second polymer is a (1 → 3)-β-d-glucopyranuronan partially substituted with single β-d-Xylp or single α-l-Fucp at position 4. The third polysaccharide is a xylo(fuco)galactan having a linear core of alternating 4-linked α-d-Gal and 3-linked β-d-Gal residues. The latter bear single β-d-Xylp or a short chain of 4-linked β-d-Xyl, 6-linked β-d-Gal, and variously linked α-l-Fuc. In FSA, these polysaccharides are sulfated at different positions and devoid of regularity. Fractions of FSA possess anticoagulant, cytotoxic, and antitumor activities, which increase with the degree of sulfation. The most sulfated fraction 2.0 M that contains mainly a sulfated fucogalactan, is about half as active as anticoagulant as the standard low-molecular mass heparin (enoxaparin).

Expression and biochemical characterization and substrate specificity of the fucoidanase from Formosa algae

A gene that encodes fucoidanase ffa2 in the marine bacterium Formosa algae strain KMM 3553T was cloned, and the protein (FFA2) was produced in Escherichia coli. Recombinant fucoidanase FFA2 was purified, and the biochemical properties of this enzyme were studied. The amino acid sequence of FFA2 showed 57% identity with known fucoidanase FcnA from Mariniflexile fucanivorans. The mass of the gene product FFA2 is 101.2 kDa (918 amino acid residues). Sequence analysis has revealed that fucoidanase FFA2 belongs to the GH107 (CAZy) family. Detailed substrate specificity was studied by using fucoidans from brown seaweeds as well as synthetic fucooligosaccharide with distinct structures. Fucoidanase FFA2 catalyzes the cleavage of (1→4)-α-glycosidic bonds in the fucoidan from Fucus evanescens within a structural fragment (→3)-α-l-Fucp2S-(1→4)-α-l-Fucp2S-(1→)n but not in a fragment (→3)-α-l-Fucp2S,4S-(1→4)-α-l-Fucp2S-(1→)n. Using synthetic di-, tetra- and octasaccharides built up of the alternative (1→4)- and (1→3)-linked α-l-Fucp2S units, the difference in substrate specificity and in the rate of enzymatic selectivity was investigated. Nonsulfated and persulfated synthetic oligosaccharides were not transformed by the enzyme. Therefore, FFA2 was specified as poly[(1→4)-α-l-fucoside-2-sulfate] glycanohydrolase. This enzyme could be used for the modification of natural fucoidans to obtain more regular and easier characterized derivatives useful for research and practical applications.

Gubenyiliu II Inhibits Breast Tumor Growth and Metastasis Associated with Decreased Heparanase Expression and Phosphorylation of ERK and AKT Pathways

Gubenyiliu II (GYII), a Traditional Chinese Medicine (TCM) formula used in our hospital, has shown beneficial effects in cancer patients. In this study, we investigated the molecular mechanisms underlying the beneficial effects of GYII on murine breast cancer models. GYII showed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model. Additionally, GYII suppressed the proliferation of 4T1 and MCF-7 cells in a dose-dependent manner. A better inhibitory effect on 4T1 cell proliferation and migration was found in the decomposed recipes (DR) of GYII. Moreover, heparanase expression and the degree of angiogenesis were reduced in tumor tissues. Western blot analysis showed decreased expression of heparanase and growth factors in the cells treated with GYII and its decomposed recipes (DR2 and DR3), and thereby a reduction in the phosphorylation of extracellular signal-regulated kinase (ERK) and serine-threonine kinase (AKT). These results suggest that GYII exerts anti-tumor growth and anti-metastatic effects in the murine breast cancer model. The anti-tumor activity of GYII and its decomposed recipes is, at least partly, associated with decreased heparanase and growth factor expression, which subsequently suppressed the activation of the ERK and AKT pathways.

Angiomodulators in cancer therapy: New perspectives

The formation of new blood vessels plays a crucial for the development and progression of pathophysiological changes associated with a variety of disorders, including carcinogenesis. Angiogenesis inhibitors (anti-angiogenics) are an important part of treatment for some types of cancer. Some natural products isolated from marine invertebrates have revealed antiangiogenic activities, which are diverse in structure and mechanisms of action. Many preclinical studies have generated new models for further modification and optimization of anti-angiogenic substances, and new information for mechanistic studies and new anti-cancer drug candidates for clinical practice. Moreover, in the last decade it has become apparent that galectins are important regulators of tumor angiogenesis, as well as microRNA. MicroRNAs have been validated to modulate endothelial cell migration or endothelial tube organization. In the present review we summarize the current knowledge regarding the role of marine-derived natural products, galectins and microRNAs in tumor angiogenesis.

Fucoidan induces Toll-like receptor 4-regulated reactive oxygen species and promotes endoplasmic reticulum stress-mediated apoptosis in lung cancer

Fucoidan, a sulfated polysaccharide extracted from brown algae, exhibits anti-cancer activity. However, the effects and mechanism of fucoidan-induced apoptosis via endoplasmic reticulum (ER) stress is unclear. In this study, we demonstrated that fucoidan prevents tumorigenesis and reduces tumor size in LLC1-xenograft male C57BL/6 mice. Fucoidan induces an ER stress response by activating the PERK-ATF4-CHOP pathway, resulting in apoptotic cell death in vitro and in vivo. Furthermore, ATF4 knockdown abolishes fucoidan-induced CHOP expression and rescues cell viability. Specifically, fucoidan increases intracellular reactive oxygen species (ROS), which increase ATF4 and CHOP in lung cancer cells. Using the ROS scavenger N-acetyl-l-cysteine (NAC), we found that ROS generation is involved in fucoidan-induced ER stress-mediated apoptosis. Moreover, via Toll-like receptor 4 (TLR4) knockdown, we demonstrated that fucoidan-induced ROS and CHOP expression were attenuated. Our study is the first to identify a novel mechanism for the antitumor activity of fucoidan. We showed that fucoidan inhibits tumor viability by activating the TLR4/ROS/ER stress axis and the downstream PERK-ATF4-CHOP pathway, leading to apoptosis and suppression of lung cancer cell progression. Together, these results indicate that fucoidan is a potential preventive and therapeutic agent for lung cancer that acts via activation of ROS-dependent ER stress pathways.

The natural compound fucoidan from New Zealand Undaria pinnatifida synergizes with the ERBB inhibitor lapatinib enhancing melanoma growth inhibition

Melanoma remains one of the most aggressive and therapy-resistant cancers. Finding new treatments to improve patient outcomes is an ongoing effort. We previously demonstrated that melanoma relies on the activation of ERBB signaling, specifically of the ERBB3/ERBB2 cascade. Here we show that melanoma tumor growth is inhibited by 60% over controls when treated with lapatinib, a clinically approved inhibitor of ERBB2/EGFR. Importantly, tumor growth is further inhibited to 85% when the natural compound fucoidan from New Zealand U. pinnatifida is integrated into the treatment regimen. Fucoidan not only enhances tumor growth inhibition, it counteracts the morbidity associated with prolonged lapatinib treatment. Fucoidan doubles the cell killing capacity of lapatinib. These effects are associated with a further decrease in AKT and NFκB signaling, two key pathways involved in melanoma cell survival. Importantly, the enhancing cell killing effects of fucoidan can be recapitulated by inhibiting ERBB3 by either a specific shRNA or a novel, selective ERBB3 neutralizing antibody, reiterating the key roles played by this receptor in melanoma. We therefore propose the use of lapatinib or specific ERBB inhibitors, in combination with fucoidan as a new treatment of melanoma that potentiates the effects of the inhibitors while protecting from their potential side effects.

An Exploratory Study on the Anti-inflammatory Effects of Fucoidan in Relation to Quality of Life in Advanced Cancer Patients

Background. Conventional anticancer therapies still cause difficulties with selective eradication and accompanying side effects that reduce patients’ quality of life (QOL). Fucoidan is extracted from seaweeds and has already exhibited broad bioactivities, including anticancer and anti-inflammatory properties, in basic studies. It is expected to enhance therapeutic efficacy and minimize side effects in cancer patients; however, despite its potential benefits, there are very few clinical trials using fucoidans. Therefore, we performed an exploratory clinical study for advanced cancer patients to examine the efficacy of fucoidans, especially focusing on inflammation in relation to QOL scores. Methods. We conducted a prospective, open-label clinical study for advanced cancer patients using fucoidans via oral administration; 20 advanced cancer patients with metastases were recruited and were given 400 mL/d fucoidan (10 mg/mL) for at least 4 weeks. Inflammatory biomarkers, including high-sensitivity C-reactive protein and various cytokines, and QOL scores were monitored before treatment, after 2 weeks, and after 4 weeks of fucoidan ingestion. Results. The main proinflammatory cytokines, including interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were significantly reduced after 2 weeks of fucoidan ingestion. QOL scores, including fatigue, stayed almost stable without significant changes during the study period. The univariate and multivariate analyses revealed that the responsiveness of IL-1β was a significant independent prognostic factor. Conclusion. This is the first study providing evidence of the anti-inflammatory effects of fucoidans for advanced cancer patients. In future studies, larger blinded, controlled trials are required to establish the efficacy of fucoidan as supportive care for cancer patients, especially those undergoing chemotherapy.

Melanoma and brown seaweed: an integrative hypothesis

Although relatively rare, melanoma accounts for 2 % of cancer diagnoses globally and accounts for about 1 % of all cancer deaths. Worldwide, the annual incidence of melanoma is 272,000 cases which vary hugely, ranging from Japan where it is incredibly infrequent, to Queensland, Australia, where it is nearly 100 times higher. Based on epidemiology and laboratory studies, there is compelling evidence suggesting that seaweed might be protective against different types of cancers such as breast cancer in seaweed consuming populations. By comparing countries where melanoma is more common with countries where it is infrequent, it is possible to construct a hypothesis for how consuming brown seaweeds which may hold clues to the differences in melanoma susceptibility between Japanese and Western nations. Unlike in these other countries, where melanoma incidence has increased dramatically over the last two decades, in Japan, rates have remained remarkably low and stable. There is limited evidence from clinical studies and animal models that have used whole seaweed or isolated fractions from seaweed and measured changes in biomarkers. They have demonstrated the effectiveness of seaweed at inhibiting melanoma development and progression. In this review, the various results will be described. Although there are several effective fractions, it is proposed that consuming whole seaweeds may hold additional benefits that could be lost by consuming only a single extract.